1. | \(53^{\circ}\) | 2. | \(37^{\circ}\) |
3. | \(45^{\circ}\) | 4. | \(60^{\circ}\) |
1. | \(45\) cm | 2. | \(30\) cm |
3. | \(15\) cm | 4. | \(25\) cm |
1. | \(X+Y\) | 2. | \(\frac{X + Y}{2}\) |
3. | \(X-Y\) | 4. | \(\frac{X - Y}{2}\) |
A plane mirror is placed at the bottom of a fish tank filled with water of refractive index \(\frac{4}{3}.\) The fish is at a height \(10\) cm above the plane mirror. An observer \(O\) is vertically above the fish outside water. The apparent distance between the fish and its image is:
1. | \(15\) cm | 2. | \(30\) cm |
3. | \(35\) cm | 4. | \(45\) cm |
1. | a convergent with power \(P=\frac{1}{3 R}\) |
2. | a convergent with power \(P=\frac{1}{6 R}\) |
3. | a divergent with power \(P=\frac{1}{3 R}\) |
4. | a divergent with power \(P=\frac{1}{6 R}\) |
If there is no emergent light through a prism of refracting angle \(60^{\circ},\) whatever may be the angle of incidence, then the minimum value of the refractive index of the material of the prism is:
1. | \(2\) | 2. | \(\sqrt{2}\) |
3. | \(1.5\) | 4. | \(\sqrt{3}\) |
The minimum magnifying power of an astronomical telescope is \(40\). If the length of the telescope is \(205\) cm, then the focal length of its field lens is:
1. \(5\) cm
2. \(200\) cm
3. \(40\) cm
4. \(140\) cm
If \(C_1,~C_2 ~\mathrm{and}~C_3\) are the critical angle of glass-air interface for red, violet and yellow color, then:
1. | \(C_3>C_2>C_1\) | 2. | \(C_1>C_2>C_3\) |
3. | \(C_1=C_2=C_3\) | 4. | \(C_1>C_3>C_2\) |
An astronomical telescope has angular magnification of \(40\) in its normal adjustment. If focal length of eyepiece is \(5\) cm, the length of the telescope is:
1. \(190\) cm
2. \(200\) cm
3. \(205\) cm
4. \(210\) cm